Composite electromagnetic isolation filters

Abstract

The present disclosure is directed to systems and methods for operating, designing, testing and verifying the performance of wireless communication devices. Specifically, the present systems and methods can passively attenuate unwanted electromagnetic interference (EMI) without degrading signal quality of predetermined frequency using a novel versatile module including a RF absorbing material in a composite medium surrounding the conducting signal lines. Utilizing varying permeability media, the present invention offer a robust platform to eliminate unwanted noise while maintaining a desirable control and power interfaces used for testing of wireless communication systems.

What is claimed is: 
     
       1. An apparatus for mitigating electromagnetic interference, comprising:
 a first strip of passive electromagnetically attenuating media; 
 a second strip of passive electromagnetically attenuating media; and 
 one or more electrical conductors extending substantially along a length of the first and second strip; 
 said one or more electrical conductors disposed in between first and second strip; 
 one or more electromagnetic signal interface ports, said electromagnetic signal interface ports in electrical communication with said one or more electrical conductors; and 
 a LC filter element in-line with said electrical conductors so as to sharpen the filter drop-off characteristic of the apparatus. 
 
     
     
       2. The apparatus of  claim 1 , said first and second strips comprising lossy media in a composite medium. 
     
     
       3. The apparatus of  claim 1 , said first and second strips disposed in close proximity to said one or more electrical conductors thereby creating an electromagnetically-isolating envelope. 
     
     
       4. The apparatus of  claim 1 , said first and second strips further comprising a media with a complex permeability, p. 
     
     
       5. The apparatus of  claim 1 , said electromagnetic signal interface ports comprising a standard networking protocol standard. 
     
     
       6. The apparatus of  claim 1 , said electromagnetic signal interface ports comprising a standard coaxial protocol standard. 
     
     
       7. The apparatus of  claim 1 , said electromagnetic signal interface ports in electrical communication with a device under test. 
     
     
       8. The apparatus of  claim 1 , further comprising one or more of said apparatus for mitigating electromagnetic interference thereby engendering an array. 
     
     
       9. The apparatus of  claim 8 , further comprising a test chamber, said array mechanically coupled to said test chamber. 
     
     
       10. The apparatus of  claim 1 , said electrical conductors comprising metal traces. 
     
     
       11. The apparatus of  claim 1 , said electrical conductors comprising copper wires. 
     
     
       12. The apparatus of  claim 1 , further comprising a solid conduit through which said electrical conductors pass. 
     
     
       13. The apparatus of  claim 1 , said apparatus being formed by a monolithic electromagnetically-isolating box into using an electromagnetically-isolating material. 
     
     
       14. The apparatus of  claim 1 , comprising a plurality of connectors for controlling a test of a plurality of different wireless communication devices under. 
     
     
       15. In an electromagnetically isolating test chamber system, a passive electromagnetic filter assembly that attenuates unwanted electromagnetic interference at or proximal to a portal penetrating into said test chamber, the filter assembly comprising:
 a housing, including mechanical mounting points for mounting to the electromagnetic test chamber, and including at least a pair of apertures penetrating said housing; 
 an electrical signal conductor, having a first end and a second end, that carries desired electrical signals along a length of said conductor between the first end of the signal conductor to the second end of the signal conductor; 
 an electromagnetically-attenuating medium, comprising a composite of conducting particles embedded in a flexible substrate, substantially surrounding the signal conductor and substantially extending the length of said signal conductor between said first and second ends thereof; and 
 a pair of electrical connectors, one at each end of said signal conductor, a first one of said connectors proximal to a first aperture in said housing and a second one of said connectors proximal to a second aperture in said housing; 
 wherein said connectors are dimensioned, shaped and configured according to a standardized commercial specification and further adapted for mating to corresponding connectors according to said standardized commercial specification; and 
 wherein said first housing aperture and first connector are suitably disposed on said housing to be in signal communication with components inside the test chamber, while said second housing aperture and second connector are suitably disposed on said housing to be in signal communication with components outside said test chamber, the filter assembly thereby being configured and arranged to provide selective signal passage through said conductor and said connectors, and to exclude unwanted electromagnetic interference from passing therethrough. 
 
     
     
       16. The assembly of  claim 15 , said signal conductor comprising a plurality of bundled conducting wires, the signal conductor terminating at either end thereof in said electrical connectors, the connectors and the plurality of bundled conducting wires being coupled at the respective ends of the wires to conform to said standardized commercial specification. 
     
     
       17. The assembly of  claim 16 , said specification comprising an Ethernet or a USB specification. 
     
     
       18. The assembly of  claim 15 , further comprising a LC filter element in-line with said signal conductor so as to sharpen the filter drop-off characteristic of the assembly. 
     
     
       19. A passive electromagnetic filter assembly, comprising:
 a housing having at least a pair of apertures penetrating said housing; 
 a filter support plate to support one or more passive filter components comprising a substantially planar plate supporting a pair of electrical connectors, one proximal to each of two opposing ends of said filter support plate, and supporting an electrical signal conductor; 
 an electromagnetically-attenuating medium, comprising a composite of conducting particles embedded in a flexible substrate, disposed around the signal conductor but permitting the signal conductor to be coupled at respective opposing ends thereof to respective ones of said pair of electrical connectors; and 
 a first isolation plate comprising a solid electromagnetically isolating slab disposed proximal to a first face of said filter support plate and including a first aperture for passage of a first of said pair of electrical connectors therethrough; and 
 a second isolation plate comprising a solid electromagnetically isolating slab disposed proximal to a second face of said filter support plate, opposing the first face of said filter support plate, and including a second aperture for passage of a second of said pair of electrical connectors therethrough. 
 
     
     
       20. The assembly of  claim 19 , said first and second isolation plates configured and arranged to securely sandwich said filter support plate between them to substantially form a three-layered assembly having the passive filter components therein. 
     
     
       21. The assembly of  claim 20 , further comprising an electromagnetically isolating gasket surrounding at least a portion of said passive filter components and disposed between the respective isolation plates and the filter support plate. 
     
     
       22. The assembly of  claim 19 , further comprising an outer housing that substantially encloses other components of the assembly, and having at least one opening therein to permit signal communication between the passive filter components in the assembly and other systems outside the assembly. 
     
     
       23. The assembly of  claim 19 , said filter support plate supporting a second passive filter component comprising a second signal conductor within a second electromagnetically-attenuating medium, said second signal conductor coupled at its ends to a second pair of electrical connectors. 
     
     
       24. The assembly of  claim 19 , further comprising a LC filter element in-line with said signal conductor so as to sharpen the filter drop-off characteristic of the assembly.